This polymer quad rail/hand guard system will fit on your Master Piece Arms 10-16" barreled upper. Easy installation by unscrewing the head cap on your barrel and removing the plastic smooth AR type hand guards. It offers four rails, one full length on top and one on the bottom and one forward rail on each sides for mounting optics, lasers, hand grips and anything else to customize your gun. Also fits carbine (16") barreled uppers. Call with questions. (gun, head cap, base mount, muzzle brake & other parts sold separately)* Fits most standard carbine length AR rifles with hand guards as well.